Grinder pumps are often used in low-pressure wastewater systems for pumping wastewater. The grinder pumps include a grinder mechanism for cutting or grinding solids or semisolid matter in the wastewater being pumped. Grinding solids and/or semisolid matter in the wastewater allows the resulting particulate effluent to be transferred through small diameter pipes without clogging.
Conventional grinder pump systems are typically equipped with level sensors and an alarm. When the wastewater reaches a certain level in the tank, the pump automatically switches on and when the wastewater in the tank falls below a certain level, the pump automatically turns off. If the level rises too high, typically another sensor activates an alarm. Conventional level sensors include mechanical float switches, sensing tubes connected to pressure transducers, ultrasonic transducers, and capacitive level sensors. Wires connect the sensors to a circuit for controlling the grinder pump and an alarm. Where a low-level sensor fails, the grinder pump may be operated in response to a high-level alarm so that the grinder pump cycles on and off and maintains the level of the wastewater near the high level position.
There is a need for further liquid level sensing assemblies for grinder pump assemblies.